1. Field of the Invention
The present invention relates to planetary gear devices mainly used in power transmission mechanisms for aircrafts, and particularly relates to a lubricating structure for such planetary gear devices.
2. Description of Related Art
In recent years, one of the key issues in aircrafts is to reduce fuel consumption from the viewpoint of reduction in operation cost and environmental conservation. Therefore, also for planetary gear devices for use in aircraft engines, reduction in power loss is required.
Conventionally, this type of planetary gear device includes a mechanism for supplying lubricant oil to gears in order to lubricate and cool the gears. However, one of main causes of power loss in the gear device is stirring resistance of lubricant oil that is supplied around the gears. It is suggested that, in order to reduce stirring resistance of lubricant oil, for example, a baffle (barrier) is provided between planet gears adjacent to each other to reduce generation of swirl flow caused due to interference of flows of lubricant oil occurring around the planet gears adjacent to each other (see, for example, Patent Document 1).
Furthermore, it is also suggested that lubricant oil is temporarily collected in a space formed in the baffle, and a portion of the collected lubricant oil is discharged in the axial direction, and another portion of the collected lubricant oil is supplied to a ring gear via a through hole formed in the baffle, to use the lubricant oil for lubricating the ring gear (see, for example, Patent Document 2). In this case, a portion of an outlet in the axial direction of the baffle is covered with a weir to store the lubricant oil to be supplied to the ring gear, thereby enabling the ring gear to be assuredly lubricated.